1. Field of the Invention
The present invention relates to a display device, and more particularly, to a light emission device emitting light using electron emission regions and a phosphor layer, and a display device using the light emission device as a light source.
2. Description of Related Art
A light emission device that includes first and second substrates facing each other with a gap therebetween, a plurality of electron emission regions provided on the first substrate, and a phosphor layer and an anode electrode provided on the second substrate is well known. The light emission device has a simplified optical member and lower power consumption than both a cold cathode fluorescent lamp (CCFL) type light emission device and a light emitting diode (LED) type light emission device.
The first and second substrates are sealed together at their peripheries using a sealing member to form a vacuum envelope. In the light emission device, electrons emitted from the electron emission regions are accelerated toward the phosphor layer by an anode voltage applied to the anode electrode, and excite the phosphor layer to emit visible light. The luminance of a light emission surface is proportional to the anode voltage.
The light emission device can be used as a light source in a display device including a non-self emissive type display panel. However, in the light emission device, when a high voltage is applied to the anode electrode to enhance the light emission intensity, arcing is generated in the vacuum envelope due to gas impurity and the charging of a non-conductor surface in the vacuum envelope. The arcing may damage the internal structure. Therefore, it is difficult to increase the anode voltage, and thus it is difficult to increase the luminance to a desired level.
In addition, the light emission device is driven to maintain a predetermined brightness over the entire light emission surface when the display device is driven. Therefore, it is difficult to improve the dynamic contrast and display quality of the screen to a sufficient level.